Active optics feedback and calibration

Abstract

An optical system includes an illumination layer, an optical combiner, and an active optics block. The illumination layer includes an array of point light sources configured to emit calibration light. The optical combiner is configured to pass visible light to a front side of the optical system and to direct the calibration light to a camera that generates an image in response to the calibration light. The image includes an array of points corresponding to the array of point light sources. The active optics block includes an adjustable lens disposed between the illumination layer and the optical combiner and is configured to pass the calibration light to the optical combiner and to focus the visible light. The active optics block is further configured to adjust an optical power of the adjustable lens based on the image of the array of points.

What is claimed is: 
     
       1. An optical system, comprising:
 an illumination layer having an array of point light sources configured to emit calibration light in an emitted pattern, wherein the illumination layer is configured to pass scene light, wherein the illumination layer is positioned to receive the scene light from a first side and pass the scene light out of a second side, wherein the illumination layer emits the calibration light from the second side; 
 an optical combiner configured to pass the scene light to a front side of the optical system and to direct the calibration light to a camera that generates an image in response to the calibration light, wherein the image includes a captured pattern of an array of points corresponding to the array of point light sources; and 
 an active optics block that includes a controller and that includes an adjustable lens disposed between the illumination layer and the optical combiner, wherein the adjustable lens is configured to pass the calibration light to the optical combiner and to focus the scene light, wherein the controller is configured to process the image to determine a distortion between the emitted pattern and the captured pattern of the array of the points included in the image, wherein the controller is configured to generate one or more control signals to vary a shape of the adjustable lens to compensate for the distortion. 
 
     
     
       2. The optical system of  claim 1 , wherein the illumination layer comprises a transparent substrate, and wherein the array of point light sources comprises a plurality of emitters disposed on the transparent substrate. 
     
     
       3. The optical system of  claim 1 , wherein the calibration light comprises infrared light. 
     
     
       4. The optical system of  claim 1 , wherein the calibration light comprises collimated light. 
     
     
       5. The optical system of  claim 1 , wherein the illumination layer comprises a lightguide for providing the array of point light sources to emit the calibration light. 
     
     
       6. The optical system of  claim 1 , wherein the active optics block further comprises at least one actuator configured to vary the shape of the adjustable lens. 
     
     
       7. The optical system of  claim 6 , wherein the adjustable lens comprises a liquid lens or a flexible polymer lens. 
     
     
       8. A method, comprising:
 emitting a first pattern of calibration light with an array of point light sources, wherein the calibration light passes through an adjustable lens and through an optical combiner towards a camera; 
 generating, with the camera, an image of a second pattern in response to the calibration light, wherein the second pattern includes an array of points corresponding to the array of point light sources; 
 receiving, with an adjustable lens controller, the image generated by the camera, wherein the calibration light is emitted by an illumination layer configured to carry the array of point light sources, wherein the illumination layer is configured to pass scene light, wherein the adjustable lens is positioned between the illumination layer and the optical combiner; 
 processing, with the adjustable lens controller, the image to determine a distortion between the first pattern and the second pattern of the array of points included in the image; and 
 generating, with the adjustable lens controller, one or more control signals to vary a shape of the adjustable lens to compensate for the distortion between the first pattern and the second pattern of the array of points included in the image. 
 
     
     
       9. The method of  claim 8 , wherein the array of point light sources comprises a plurality of vertical cavity surface emitting laser (VCSEL) diodes disposed on a transparent substrate. 
     
     
       10. The method of  claim 8 , wherein the calibration light comprises infrared light. 
     
     
       11. The method of  claim 8 , wherein the array of point light sources comprises a lightguide for emitting the calibration light. 
     
     
       12. The method of  claim 8 , wherein generating the one or more control signals comprises sending the one or more control signals to at least one actuator to vary the shape of the adjustable lens. 
     
     
       13. The method of  claim 12 , wherein the adjustable lens comprises a liquid lens or a flexible polymer lens. 
     
     
       14. The method of  claim 8 , wherein processing the image to determine the distortion comprises determining a location of at least one of the points included in the second pattern of the image. 
     
     
       15. An optical system, comprising:
 a camera configured to generate an image in response to calibration light; 
 an illumination layer having an array of point light sources configured to emit the calibration light in a first pattern, wherein the illumination layer is configured to pass visible light, wherein the illumination layer is positioned to receive the visible light from a first side and pass the visible light out of a second side, wherein the illumination layer emits the calibration light from the second side; 
 an optical combiner configured to pass the visible light to a front side of the optical system and to direct the calibration light to the camera, wherein the image generated by the camera includes a second pattern of an array of points corresponding to the array of point light sources; 
 an adjustable lens disposed between the illumination layer and the optical combiner, the adjustable lens configured to pass the calibration light to the optical combiner and to focus the visible light; and 
 a controller configured to: (a) process the image to determine a distortion between the first pattern and the second pattern of the array of the points included in the image, and (b) generate one or more control signals to adjust a shape of the adjustable lens to compensate for the distortion. 
 
     
     
       16. The optical system of  claim 15 , wherein the illumination layer comprises a transparent substrate, and wherein the array of point light sources comprises a plurality of vertical cavity surface emitting laser (VCSEL) diodes disposed on the transparent substrate. 
     
     
       17. The optical system of  claim 15 , wherein the illumination layer comprises a lightguide for providing the array of point light sources to emit the calibration light. 
     
     
       18. The optical system of  claim 15 , further comprising at least one actuator configured to vary the shape of the adjustable lens. 
     
     
       19. The optical system of  claim 18 , wherein the adjustable lens comprises a liquid lens or a flexible polymer lens.